Data transmission method for ultra-low latency and highly-reliable communication in wireless communication system, and apparatus therefor

ABSTRACT

Provided are a repetitive transmission method for ultra-low latency and highly-reliable communication in a wireless communication system, and an apparatus therefor. A method for transmitting data by a terminal according to an embodiment of the present invention comprises the steps of: receiving information on the repetition number of transmission for a physical uplink shared channel (PUSCH) from a base station; receiving, from the base station, information on frequency hopping applied to the the PUSCH repetition configuring the the PUSCH repetition; determining a frequency resource for the PUSCH repetition based on the information on the frequency hopping; and performing the the PUSCH repetition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage of International Application No.PCT/KR2020/010313, filed on Aug. 5, 2020, which claims the benefit ofpriority to Korean Application(s) No. 10-2019-0097246, filed on Aug. 9,2019 and 10-2019-0097247, filed on Aug. 9, 2019 and 10-2019-0097248,filed on Aug. 9, 2019 and 10-2019-0169079, filed on Dec. 17, 2019 and10-2019-0169080, filed on Dec. 17, 2019 and 10-2019-0172420, filed onDec. 20, 2019 in the Korean Intellectual Property Office, thedisclosures of which are incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE Field of the disclosure

The present disclosure relates to a wireless communication system, andmore specifically, to a data transmission method and apparatus forultra-low latency and highly-reliable communication.

Related Art

For communication in various application fields corresponding to 5GUltra-Reliable and Low Latency Communication (URLLC) scenarios, dataneeds to be transmitted rapidly and stably. However, when a terminalmoves in a direction in which a channel deteriorates in an environmentin which the terminal moves rapidly, an error may be generated in data,and thus a situation in which the corresponding data needs to beretransmitted may occur.

In the case of normal data transmission, there is no problem even ifdata is retransmitted. However, in the case of transmitting URLLC data,a problem of increased latency may occur if retransmission is performed.

SUMMARY

A technical object of the present disclosure to provide a method forrepetitively transmitting data with stability and a short delay.

Another technical object of the present disclosure is to provide anapparatus for stably transmitting used data with a short delay.

Yet another technical object of the present disclosure is to provide amethod for transmitting data based on a code block group (CBG) in ascenario such as URLLC in which the amount of data is relatively smalland data needs to be stably transmitted with a short delay.

Still another technical object of the present disclosure is to providean apparatus for transmitting data based on a CBG in a scenario such asURLLC in which the amount of data is relatively small and data needs tobe stably transmitted with a short delay.

According to an aspect of the present disclosure, a method fortransmitting data by a UE in a wireless communication system includesreceiving downlink control information including information on arepetition number of transmission for uplink data and information onfrequency hopping from a base station, configuring a plurality ofphysical uplink shared channels (PUSCHs) corresponding to the repetitionnumber of transmission, the uplink data being equally mapped to thePUSCHs, and determining frequency resources for transmission of thePUSCHs based on the information on frequency hopping, wherein a range ofthe frequency hopping may change according to a size of a bandwidth part(BWP) activated for transmission of the uplink data.

According to an aspect, the uplink control information may furtherinclude information on a length of a mini-slot used for repetitivetransmission of the uplink data, and the PUSCHs may be performed inunits of the mini-slot.

According to another aspect, the frequency resources may be frequencyresources corresponding to both ends of the activated bandwidth part.

According to another aspect, the method may further include transmittingchannel quality information to the base station before the receivingstep, wherein the information on frequency hopping may be determinedbased on the channel quality information.

According to another aspect, the information on frequency hoppingincludes information on whether the frequency hopping is applied andinformation on a frequency hopping pattern.

According to another aspect, the method may further include receiving,from the base station, information on a default repetition number oftransmission for uplink transmission before the receiving step, whereinthe downlink control information may include information on a differencebetween the default repetition number of transmission and an actualrepetition number of transmission of the uplink data.

According to another aspect of the present disclosure, a method forreceiving data by a base station in a wireless communication systemincludes determining whether to apply frequency hopping to uplink dataof a UE based on channel quality information received from the UE,transmitting downlink control information including information on arepetition number of transmissions for the uplink data and informationon the frequency hopping to the UE, and receiving, from the UE, aplurality of PUSCHs corresponding to the repetition number oftransmission through frequency resources determined based on theinformation on the frequency hopping, wherein the uplink data is equallymapped to the plurality of PUSCHs, and a range of the frequency hoppingmay change according to a size of a bandwidth part activated in the UEfor transmission of the uplink data.

According to another aspect of the present disclosure, a method fortransmitting data by a base station in a wireless communication systemincludes transmitting, to a UE, a plurality of physical downlink sharedchannels (PDSCHs) to which first data is equally mapped, receiving afeedback for the plurality of PDSCHs from the UE, and determining arepetition number of transmission for second data based on the feedback.

According to one aspect, the method may further include transmitting, tothe UE, a radio resource control (RRC) message including information onat least one of a maximum repetition number of transmission and adefault repetition number of transmission for downlink data before thetransmitting step, wherein the plurality of PDSCHs may be configuredaccording to the maximum repetition number of transmission or therepetition default number transmission.

According to another aspect, the feedback may include ACK or NACK foreach of the plurality of PDSCHs, and the repetition number oftransmission for the second data may be determined based on at least oneof the number of ACKs and the number of NACKs included in the feedback.

According to another aspect, the determining step may include changingthe repetition number of transmission for the second data if the numberof ACKs or NACKs included in the feedback is equal to or greater than areference value or a ratio between the number of ACKs and the number ofNACKs included in the feedback is equal to or greater than a referenceratio.

According to another aspect, the repetition number of transmission forthe second data may be changed when a channel environment when thesecond data is transmitted corresponds to a channel environment when thefirst data is transmitted.

According to another aspect, the method may further include transmittingdownlink control information including information on the repetitionnumber of transmission for the second data to the UE after thedetermining step.

According to another aspect, the downlink control information mayinclude information on a difference between the repetition number oftransmission for the first data and the repetition number oftransmission for the second data.

According to another aspect of the present disclosure, a method fortransmitting data by a UE in a wireless communication system includesconfiguring a plurality of physical uplink shared channels (PUSCHs) towhich first data is equally mapped and transmitting the PUSCHs to a basestation, receiving a feedback for the plurality of PUSCHs from the basestation, receiving information on a repetition number of transmissionsdetermined based on the feedback from the base station, and performingrepetition of second data based on the information on the repetitionnumber of transmission.

According to another aspect of the present disclosure, a method fortransmitting data by a UE in a wireless communication system includesreceiving a feedback for uplink data transmitted by the UE from a basestation, determining whether to perform retransmission of the uplinkdata based on the feedback, setting a size of a code block group of theuplink data based on a type of the uplink data when the uplink data isretransmitted, and retransmitting the uplink data in units of theadjusted code block group.

According to one aspect, the uplink data may include URLLC(Ultra-Reliable and Low Latency Communication) data, and the size of thecode block group may be set to be less than the size of a code blockgroup for retransmission of enhanced mobile broadband (eMBB) data.

According to another aspect, the method may further include, before thereceiving step, receiving information on the size of a code block groupfor retransmission of the URLLC data from the base station through atleast one of a radio resource control (RRC) message and downlink controlinformation.

According to another aspect, the information on the size of the codeblock group may be information on a maximum number of code block groupsper transport block for the URLLC data.

According to another aspect, the maximum number of code block groups pertransport block for the URLLC data may be set separately from a maximumnumber of code block groups per transport block for the eMBB data.

According to another aspect of the present disclosure, a method fortransmitting data by a base station in a wireless communication systemmay include receiving a feedback for downlink data transmitted by thebase station from a UE, determining whether to perform retransmission ofthe downlink data based on the feedback, setting a size of a code blockgroup of the downlink data based on a type of the downlink data when thedownlink data is retransmitted, and retransmitting the downlink in unitsof the adjusted code block group.

According to another aspect of the present disclosure, a method fortransmitting data by a UE in a wireless communication system isprovided. The data transmission method includes receiving information ona repetition number of transmission for a physical uplink shared channel(PUSCH) from a base station, receiving information on frequency hoppingapplied to the PUSCH repetition from the base station, configuring thePUSCH repetition, determining frequency resources for the PUSCHrepetition based on the information on the frequency hopping, andperforming the PUSCH repetition.

According to another aspect of the present disclosure, a range of thefrequency hopping is changed according to a size of a bandwidth part(BWP) activated for the PUSCH repetition.

According to another aspect of the present disclosure, the method mayfurther include receiving information on a length of a mini-slot usedfor the PUSCH repetition, wherein the PUSCH repetition is performed inunits of the mini-slot.

According to another aspect of the present disclosure, the frequencyresources are frequency resources corresponding to both ends of theactivated bandwidth part.

According to another aspect of the present disclosure, the datatransmission method further includes transmitting channel qualityinformation to the base station, wherein the information on thefrequency hopping is determined based on the channel qualityinformation.

According to another aspect of the present disclosure, the informationon the frequency hopping includes information on whether the frequencyhopping is applied and information on a frequency hopping pattern.

According to another aspect of the present disclosure, the informationon the repetition number of transmission includes information on adefault repetition number of transmission and information on adifference between the default repetition number of transmission and anactual number of times of the PUSCH repetition.

According to another aspect of the present disclosure, the informationon the repetition number of transmission includes at least one of amaximum repetition number of transmission and the default repetitionnumber of transmission as a radio resource control (RRC) message,wherein the PUSCH repetition is configured according to the maximumrepetition number of transmission or the default repetition number oftransmission.

According to another aspect of the present disclosure, the datatransmission method further includes receiving, from the base station,information on a repetition number of new transmission determined basedon ACK or NACK for the PUSCH repetition and performing transmission of anew PUSCH based on the information on the repetition number of newtransmission.

According to another aspect of the present disclosure, the informationon the repetition number of new transmission is changed if the number ofACKs or NACKs is equal to or greater than a reference value or a ratiobetween the number of ACKs and the number of NACKs is equal to orgreater than a reference ratio.

According to another aspect of the present disclosure, a method fortransmitting data by a base station in a wireless communication systemis provided. The data transmission method includes transmittinginformation on a repetition number of transmission for a physicaldownlink shared channel (PDSCH) to a UE, transmitting information onfrequency hopping applied to the PUSCH repetition to the UE, configuringthe PDSCH repetition, determining frequency resources for the PDSCHrepetition based on the information on the frequency hopping, andperforming the PDSCH repetition.

According to another aspect of the present disclosure, a range of thefrequency hopping is changed according to a size of a bandwidth part(BWP) activated for the PDSCH repetition.

According to another aspect of the present disclosure, the datatransmission method further includes transmitting information on alength of a mini-slot used for the PDSCH repetition to the UE, whereinrepetition transmission of the PDSCH is performed in units of themini-slot.

According to another aspect of the present disclosure, the frequencyresources are frequency resources corresponding to both ends of theactivated bandwidth part.

According to another aspect of the present disclosure, the datatransmission method further includes receiving channel qualityinformation from the UE, wherein the information on the frequencyhopping is determined based on the channel quality information.

According to another aspect of the present disclosure, the informationon the frequency hopping includes information on whether the frequencyhopping is applied and information on a frequency hopping pattern.

According to another aspect of the present disclosure, the informationon the repetition number of transmission includes information on adefault repetition number of transmission and information on adifference between the default repetition number of transmission and anactual number of times of the PDSCH repetition.

According to another aspect of the present disclosure, the informationon the repetition number of transmissions includes at least one of amaximum repetition number of transmission and a default repetitionnumber of transmission as an RRC message, wherein the PDSCH repetitionis configured according to the maximum repetition number of transmissionor the default repetition number of transmission.

According to another aspect of the present disclosure, the datatransmission method includes transmitting information on a repetitionnumber of new transmission determined based on ACK or NACK for the PDSCHrepetition to the UE and performing a new PDSCH repetition based on therepetition number of new transmission.

According to another aspect of the present disclosure, the informationon the repetition number of new transmission is changed if the number ofACKs or NACKs is equal to or greater than a reference value or a ratiobetween the number of ACKs and the number of NACKs is equal to orgreater than a reference ratio.

Advantageous Effects

According to the present invention, when data corresponds to URLLC, atransmitter can transmit the same data twice or more using frequencyhopping based on a mini-slot, and thus the data can be transmitted morerapidly and stably.

In addition, the repetition number of data transmission can beoptimized, and thus overhead of HARQ feedback can be reduced.

Furthermore, when URLLC data is retransmitted according to HARQ, a timedelay can be reduced and retransmission may be performed moreefficiently in terms of resource allocation and resource utilizationrequired for transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual diagram illustrating a wireless communicationsystem according to an embodiment of the present disclosure.

FIG. 2 is an exemplary diagram illustrating an NR system to which a datatransmission method according to an embodiment of the present disclosureis applicable.

FIG. 3 is a diagram illustrating a slot structure used in the datatransmission method according to an embodiment of the presentdisclosure.

FIG. 4 is a diagram for describing a mini-slot used in the datatransmission method according to an embodiment of the presentdisclosure.

FIG. 5 is a diagram illustrating an example of a frequency allocationmethod and a BWP to which the technical features of the presentdisclosure are applicable.

FIG. 6 is a diagram illustrating an example of a bandwidth adaptationmethod for transmitting multiple BWPs and BWPs while changing the sameto which the technical features of the present disclosure areapplicable.

FIG. 7 to FIG. 13 are flowcharts showing a frequency hopping methodaccording to an embodiment of the present disclosure.

FIG. 14 is a flowchart showing a data transmission method according toan embodiment of the present disclosure.

FIG. 15 is a flowchart showing a data transmission method according toanother embodiment of the present disclosure.

FIG. 16 is a flowchart showing a data transmission method according toanother embodiment of the present disclosure.

FIG. 17 is a diagram for describing the concept of a code block groupapplied to the present disclosure.

FIG. 18 illustrates a configuration of a PDSCH serving cell applied toan embodiment of the present disclosure.

FIG. 19 illustrates a configuration of a PUSCH serving cell applied toan embodiment of the present disclosure.

FIG. 20 is a diagram for describing a case of retransmitting eMBB dataaccording to an embodiment.

FIG. 21 is a diagram for describing a case of retransmitting URLLC dataaccording to an embodiment.

FIG. 22 is a flowchart showing a data transmission method according toanother embodiment of the present disclosure.

FIG. 23 is a block diagram showing a wireless communication system inwhich an embodiment of the present disclosure is implemented.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present disclosure can be modified in various manners and can havevarious embodiments, and specific embodiments are illustrated in thedrawings and described in detail in the detailed description. However,this is not intended to limit the present disclosure to specificembodiments and the present disclosure includes all modifications,equivalents and substitutions included in the spirit and scope of thepresent invention. In the drawings, like reference numerals are used forlike elements.

While terms, such as “first”, “second”, “A”, “B”, etc. may be used todescribe various components, such components must not be limited by theabove terms. The above terms are used only to distinguish one componentfrom another. For example, a first component may be referred to as asecond component, and similarly, the second component may also bereferred to as the first component without departing from the scope ofthe present disclosure. The term “and/or” includes combinations of aplurality of related items or any of a plurality of related items.

When an element is “coupled” or “connected” to another element, itshould be understood that a third element may be present between the twoelements although the element may be directly coupled or connected tothe other element. When an element is “directly coupled” or “directlyconnected” to another element, it should be understood that no elementis present between the two elements.

The terms used in the present disclosure are only used to describespecific embodiments, and are not intended to limit the presentinvention. The singular expression includes the plural expression unlessthe context clearly dictates otherwise. In the present disclosure, termssuch as “comprise” or “have” are intended to designate that a feature,number, step, operation, component, part, or combination thereofdescribed in the specification exists, but it is to be understood thatthis does not preclude the possibility of addition or existence ofnumbers, steps, operations, components, parts, or combinations thereof.

All the terms that are technical, scientific or otherwise agree with themeanings as understood by a person skilled in the art unless defined tothe contrary. Common terms as found in dictionaries should beinterpreted in the context of the related technical writings not tooideally or impractically unless this disclosure expressly defines themso.

Hereinafter, preferred embodiments according to the present disclosurewill be described in detail with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram illustrating a wireless communicationsystem according to an embodiment of the present disclosure.

Referring to FIG. 1 , a wireless communication system 100 may include aplurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2,130-1, 130-2, 130-3, 130-4, 130-5, and 130-6.

Each of the plurality of communication nodes may support at least onecommunication protocol. For example, each of the plurality ofcommunication nodes may support a code division multiple access (CDMA)based communication protocol, a wideband CDMA (WCDMA) basedcommunication protocol, a time division multiple access (TDMA) basedcommunication protocol, a frequency division multiple access (FDMA)based communication protocol, an orthogonal frequency divisionmultiplexing (OFDM) based communication protocol, an orthogonalfrequency division multiple access (OFDMA) based communication protocol,a single carrier (SC)-FDMA based communication protocol, anon-orthogonal multiplexing access (NOMA) based communication protocol,a space division multiple access (SDMA) based communication protocol,and the like.

The wireless communication system 100 includes a plurality of basestations 110-1, 110-2, 110-3, 120-1, and 120-2 and a plurality of userequipments (UEs) 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6.

Each of the first base station 110-1, the second base station 110-2, andthe third base station 110-3 may form a macro cell. Each of the fourthbase station 120-1 and the fifth base station 120-2 may form a smallcell. The fourth base station 120-1, the third UE 130-3, and the fourthUE 130-4 may belong to the coverage of the first base station 110-1. Thesecond UE 130-2, the fourth UE 130-4, and the fifth UE 130-5 may belongto the coverage of the second base station 110-2. The fifth base station120-2, the fourth UE 130-4, the fifth UE 130-5, and the sixth UE 130-6may belong to the coverage of the third base station 110-3. The first UE130-1 may belong to the coverage of the fourth base station 120-1. Thesixth UE 130-6 may belong to the coverage of the fifth base station120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1,and 120-2 may be referred to as a NodeB, an evolved NodeB, a nextgeneration Node B (gNB), a base transceiver station (BTS), a radio basestation, a radio transceiver, an access point, an access node, a roadside unit (RSU), a digital unit (DU), a cloud digital unit (CDU), aradio remote head (RRH), a radio unit (RU), a transmission point (TP), atransmission and reception point (TRP), a relay node, and the like. Eachof the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and130-6 may be referred to as a terminal, an access terminal, a mobileterminal, a station, a subscriber station, a mobile station, a portablesubscriber station, a node, a device, and the like.

Each of the plurality of communication nodes 110-1, 110-2, 110-3, 120-1,120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may support cellularcommunication (e.g., long term evolution (LTE), LTE-advanced (LTE-A),new radio (NR), etc. defined in 3rd generation partnership project(3GPP) standards). The plurality of base stations 110-1, 110-2, 110-3,120-1, and 120-2 may operate in different frequency bands or may operatein the same frequency band. The plurality of base stations 110-1, 110-2,110-3, 120-1, and 120-2 may be connected to each other through an idealbackhaul or a non-ideal backhaul and exchange information through theideal backhaul or the non-ideal backhaul. The plurality of base stations110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to a core network(not shown) through an ideal backhaul or a non-ideal backhaul. Theplurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 maytransmit a signal received from the core network to the correspondingterminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6) and transmitsignals received from the corresponding terminals 130-1, 130-2, 130-3,130-4, 130-5 and 130-6 to the core network.

Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and120-2 may support OFDMA based downlink transmission and OFDMA or SC-FDMAbased uplink transmission. In addition, each of the plurality of basestations 110-1, 110-2, 110-3, 120-1, and 120-2 may support multipleinput multiple output (MIMO) transmission (e.g., single user (SU)-MIMO,multi-user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP)transmission, carrier aggregation transmission, transmission in anunlicensed band, device-to-device (D2D) communication (or proximityservices (ProSe)), etc. Here, the plurality of UEs 130-1, 130-2, 130-3,130-4, 130-5, and 130-6 can perform operations corresponding to the basestations 110-1, 110-2, 110-3, 120-1, and 120-2 and/or operationssupported by the base stations 110-1, 110-2, 110-3, 120-1, and 120-2.

For example, the second base station 110-2 may transmit a signal to thefourth UE 130-4 according to SU-MIMO, and the fourth UE 130-4 mayreceive the signal from the second base station 110-2 according toSU-MIMO. Alternatively, the second base station 110-2 may transmit asignal to the fourth UE 130-4 and the fifth UE 130-5 according toMU-MIMO, and the fourth UE 130-4 and the fifth UE 130-5 may receive thesignal from the second base station 110-2 according to MU-MIMO. Thefirst base station 110-1, the second base station 110-2, and the thirdbase station 110-3 may transmit signals to the fourth UE 130-4 accordingto CoMP, and the fourth UTE 130-4 may receive the signals from the firstbase station 110-1, the second base station 110-2, and the third basestation 110-3 according to CoMP. The plurality of base stations 110-1,110-2, 110-3, 120-1, and 120-2 may transmit/receive signals to/from theUEs 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 belonging to thecoverages thereof according to CA.

Each of the first base station 110-1, the second base station 110-2, andthe third base station 110-3 may coordinate D2D communication betweenthe fourth UE 130-4 and the fifth UE 130-5, and the fourth UE 130-4 andthe fifth UE 130-5 may perform D2D communication according tocoordination of the second base station 110-2 and the third base station110-3.

Hereinafter, even when a method (e.g., transmission or reception of asignal) performed in a first communication node among communicationnodes is described, a second communication node corresponding theretomay perform a method (e.g., reception or transmission of a signal)corresponding to the method performed in the first communication node.That is, when the operation of a UE is described, the corresponding basestation may perform an operation corresponding to the operation of theUE. On the other hand, when the operation of a base station isdescribed, the corresponding UE may perform an operation correspondingto the operation of the base station.

Hereinafter, downlink (DL) means communication from a base station to aUE, and uplink (UL) means communication from a UE to a base station. Ondownlink, a transmitter may be a part of a base station and a receivermay be a part of a UE. On uplink, the transmitter may be a part of theUE and the receiver may be a part of the base station.

Recently, the amount of information exchanged through a communicationnetwork has increased with rapid spread of smartphones and Internet ofThings (IoT) terminals. Accordingly, in the next-generation wirelessaccess technology, an environment (e.g., enhanced mobile broadbandcommunication) in which faster services are provided to more users thanconventional communication systems (or conventional radio accesstechnology) needs to be considered. To this end, design of acommunication system in consideration of machine type communication(MTC) providing services by connecting a plurality of devices andobjects is under discussion. In addition, design of a communicationsystem (e.g., URLLC) considering services and/or terminals sensitive toreliability and/or latency of communication is also under discussion.

Hereinafter, for convenience of description, the next-generation radioaccess technology is referred to as new radio access technology (RAT)and a wireless communication system to which the New RAT is applied isreferred to as a new radio (NR) system in this description.

FIG. 2 is an exemplary diagram illustrating an NR system to which a datatransmission method according to an embodiment of the present disclosureis applicable.

Referring to FIG. 2 , the next generation-radio access network (NG-RAN)is composed of gNBs that provide a control plane (RRC) protocoltermination for an NG-RA user plane (SDAP/PDCP/RLC/MAC/PHY) and UEs.(NG-RAN may also include an eNB which is an existing LTE base station.)Here, NG-C represents a control plane interface used for an NG2reference point between the NG-RAN and a 5-generation core (5GC). NG-Urepresents a user plane interface used for an NG3 reference pointbetween the NG-RAN and the SGC.

gNBs are interconnected through an Xn interface and connected to the 5GCthrough an NG interface. More specifically, the gNBs are connected to anaccess and mobility management function (AMF) through the NG-C interfaceand connected to a user plane function (UPF) through the NG-U interface.

In the NR system of FIG. 2 , multiple numerologies may be supported.Here, a numerology may be defined by a subcarrier spacing (SCS) and acyclic prefix (CP) overhead. Here, a plurality of subcarrier spacingsmay be derived by scaling a basic subcarrier spacing by an integer.Further, a numerology to be used may be selected independently of afrequency band although it is assumed that a very low subcarrier spacingis not used at a very high carrier frequency.

In addition, in the NR system, various frame structures according to anumber of numerologies may be supported. Hereinafter, an OFDM numerologyand a frame structure used in a data transmission method according to anembodiment of the present disclosure will be described with reference toFIG. 3 .

FIG. 3 is a diagram illustrating a slot structure used in a datatransmission method according to an embodiment of the presentdisclosure.

A time division duplexing (TDD) considered in the NR system is astructure in which both uplink (UL) and downlink (DL) are processed inone slot (or subframe). This is for the purpose of minimizing thelatency of data transmission in a TDD system and may be referred to as aself-contained structure or a self-contained slot.

Referring to FIG. 3 , one slot may include 14 OFDM symbols (12 OFDMsymbols in case of using extended CP. In FIG. 3 , a region 310 indicatesa downlink control region and region 320 indicates an uplink controlregion. Here, unlike shown in FIG. 3 , the number of symbols used forthe downlink and uplink control regions in one slot may be greater thanone. Regions (that is, regions without indications) other than theregions 310 and 320 may be used for transmission of downlink data oruplink data. That is, uplink control information and downlink controlinformation may be transmitted in one slot. Further, in the case ofdata, uplink data and downlink data may be transmitted in one slot.

When the structure shown in FIG. 3 is used, downlink transmission anduplink transmission are sequentially performed within one slot, andtransmission of downlink data and reception of uplink ACK/NACK may beperformed. Accordingly, when an error is generated in data transmission,a time required for data retransmission can be reduced. In this manner,a delay associated with data transmission can be minimized.

In the slot structure as shown in FIG. 3 , a time gap is required for aprocess in which a base station and/or a UE switch from a transmissionmode to a reception mode or switch from the reception mode to thetransmission mode. With respect to the time gap, some OFDM symbols maybe set as a guard period (GP) when uplink transmission is performedafter downlink transmission in the slot.

FIG. 4 is a diagram for describing a mini-slot used in the datatransmission method according to an embodiment of the presentdisclosure.

According to an embodiment of the present disclosure, in addition toslot-based scheduling for efficient support of URLLC, mini-slot-basedscheduling may be supported. (A mini-slot-based transmission method isalso called a non-slot transmission method.) A mini-slot is a minimumscheduling unit by a base station and can be transmitted in unitssmaller than a slot (1 to 13 symbols). For example, a mini-slot may becomposed of 2, 4, or 7 OFDM symbols.

A mini-slot can be started in any OFDM symbol in a slot as shown in FIG.4 . Although FIG. 4 shows two mini-slots having different lengths (thenumber of OFDM symbols) in one slot, this is for illustrative purposesonly, and when a plurality of mini-slots are included in one slot, themini-slots may have the same number of OFDM symbols.

In the NR system, data needs to be transmitted stably and rapidly withalmost no errors for communication in various application fieldscorresponding to V2X (Vehicle to Everything) and URLLC scenarios. Inparticular, when a UE moves in a direction in which a channeldeteriorates in an environment in which the UE moves rapidly, an errormay occur when a base station sets a transmission format and transmitsdata based on CQI fed back from the UE to the base station, which maycause retransmission to be highly likely to occur. In case oftransmitting general data such as enhanced mobile broadband (eMBB) data,there is no problem even if retransmission occurs. However, in the caseof URLLC data, a problem may be generated due to a latency caused byretransmission when retransmission occurs. In V2X scenarios, URLLCscenarios, and the like, in most cases, the amount of transmitted userdata is not large, and thus using of some additional resources may notbe a big burden. Rather, if an error occurs and a delay increases due toretransmission caused by the error, this may be worse. Therefore, in thepresent disclosure, the same data can be repetitively or redundantlytransmitted or duplicated in the following method. The data transmissionmethod according to the present disclosure can be applied to variousscenarios of URLLC as well as vehicle communication such as V2X.

Hereinafter, resource allocation in the NR system will be described.

In the NR system, a specific number (e.g., a maximum of 4 for each ofdownlink and uplink) of bandwidth parts (BWPs) may be defined. A BWP (orcarrier BWP) is a set of consecutive PRBs and may be represented asconsecutive subsets of common RBs (CRBs). Each RB in a CRB may startwith CRB0 and may be represented by CRB1, CRB2, and the like.

<Repetitive Transmission Method Using Frequency Hopping and ApparatusTherefor>

FIG. 5 is a diagram illustrating an example of a frequency allocationmethod and BWPs to which the technical features of the presentdisclosure are applicable.

Referring to FIG. 5 , a plurality of BWPs may be defined in a CRB grid.A reference point (which may be referred to as a common reference point,a starting point, or the like) of the CRB grid is called “point A” inNR. The point A is indicated by RMSI (i.e., SIB1). Specifically, afrequency offset between a frequency band in which an SS/PBCH block istransmitted and the point A may be indicated through the RMSI. The pointA corresponds to the first subcarrier of CRB0 . In addition, the point Amay be a point at which a variable “k” indicating a frequency band of anRE in NR is set to 0. The plurality of BWPs illustrated in FIG. 5 areconfigured as one cell (e.g., a primary cell (PCell)). The plurality ofBWPs may be configured for each cell individually or in common.

Referring to FIG. 5 , each BWP may be defined by a size and a startingpoint from CRB0 . For example, the first BWP, that is, BWP #0, may bedefined by the starting point through an offset from CRB0 , and the sizeof BWP #1 may be determined through a size for BWP #0. BWPs may bedefined to overlap within the entire channel bandwidth (CBW).

A specific number (e.g., a maximum of 4 for each of downlink and uplink)of BWPs may be configured for a UE. In the 3GPP Release 15 standard,even if a plurality of BWPs is configured, only a specific number (e.g.,one) of BWPs can be activated for each cell for a given time. In thefollowing standards, a plurality of BWPs may be activated for a giventime. However, when a supplementary uplink (SUL) carrier is configuredfor a UE, up to 4 BWPs may be additionally configured in an SUL carrier,and one BWP may be activated for a given time. The number ofconfigurable BWPs or the number of activated BWPs may be commonly orindividually configured for UL and DL. In addition, the numerologyand/or CP for a DL BWP, the numerology and/or the CP for a UL BWP may beconfigured in the UE through DL signaling. The UE may receive a PDSCH, aPDCCH, a channel state information (CSI) RS and/or a tracking RS (TRS)only in an active DL BWP. In addition, the UE may transmit a PUSCHand/or a physical uplink control channel (PUCCH) only in an active ULBWP.

FIG. 6 is a diagram illustrating an example of bandwidth adaptation inwhich multiple BWPs are used while being temporally changed to which thetechnical features of the present disclosure are applicable.

In FIG. 6 , a situation in which 3 BWPs are configured is assumed. Thefirst BWP may span a 40 MHz band and a subcarrier spacing of 15 kHz maybe applied thereto. The second BWP may span a 10 MHz band and asubcarrier spacing of 15 kHz may be applied thereto. The third BWP mayspan a 20 MHz band and a subcarrier spacing of 60 kHz may be appliedthereto. A UE may configure at least one of the 3 BWPs as an active BWPand may perform UL and/or DL data communication through the active BWP.

Time resources may be indicated in a manner of indicating a timedifference/offset based on a transmission time of a PDCCH for DL or ULresource allocation. For example, a starting point of a PDSCH/PUSCHcorresponding to the PDCCH and the number of symbols occupied by thePDSCH/PUSCH may be indicated.

In the NR system, carrier aggregation (CA) may be supported as inLTE/LTE-A. That is, it is possible to increase a bandwidth byaggregating consecutive or non-consecutive component carriers (CCs) andto increase a bit rate as a result. Each CC may correspond to a(serving) cell, and each CC/cell may be divided into a primary servingcell (PSC)/primary CC (PCC) or a secondary serving cell (SSC)/secondaryCC (SCC).

In addition, single-beam and multi-beam forming can be supported in theNR system.

A network may deploy a single beam or multiple beams. Different beamsmay be used at different times. Regardless of whether a single beam ormultiple beams are deployed, it may be necessary to indicate a resourceto be monitored for control channel monitoring from the viewpoint of aUE. In particular, the same control channel may be transmitted multipletimes when multiple beams are used or repetition is used from theviewpoint of a UE.

For communication in various application fields corresponding to V2X(Vehicle to Everything) and URLLC scenarios in the NR system, data to betransmitted needs to be transmitted stably and rapidly with almost noerrors. In particular, if a UE moves in a direction in which a channeldeteriorates in an environment in which the UE moves rapidly, an errormay occur when a base station sets a transmission format and transmitsdata based on CQI fed back to from the UE to the base station, which maycause retransmission to be highly likely to occur. In case oftransmitting general data such as eMBB data, there is no problem even ifretransmission occurs. However, in the case of URLLC data, a problem maybe generated due to a latency caused by retransmission if retransmissionoccurs. In V2X scenarios, URLLC scenarios, and the like, in most cases,the amount of transmitted user data is not large and thus using someadditional resources may not be a big burden. Rather, if an error occursand a delay increases due to retransmission caused by the error, thismay be worse. Therefore, in the present disclosure, the same data can berepetitively or redundantly transmitted or duplicated through thefollowing method. The data transmission method according to the presentdisclosure can be applied to various scenarios of URLLC as well asvehicle communication such as V2X.

FIG. 7 to FIG. 13 are flowcharts illustrating a frequency hopping methodaccording to an embodiment of the present disclosure.

According to the present embodiment, when a transmitter redundantly orrepetitively transmits the same information (same data) to a receiver,frequency hopping (FH) may be performed in the frequency domain. Here,when the transmitter is a UE, the receiver may be a base station oranother UE. When the transmitter is a base station, the receiver may bea UE.

As an example, the UE may perform frequency hopping in the frequencydomain in units of a mini-slot when repetitively or redundantlytransmitting the same data to the base station. For example, afterconfiguring a plurality of PUSCHs corresponding to the repetition numberof transmission, the UE may transmit a first PUSCH to the base stationin a first mini-slot using a first frequency and transmit a second PUSCHto the base station in a second mini-slot temporally adjacent to thefirst mini-slot using a second frequency according to frequency hopping.Here, the same uplink data may be equally mapped to each PUSCH.

As another example, the base station may perform frequency hopping inthe frequency domain in units of a mini-slot when repetitively orredundantly transmitting the same data to the UE. For example, afterconfiguring a plurality of PDSCHs corresponding to the repetition numberof transmission, the base station may transmit a first PDSCH to the UEin a first mini-slot using a first frequency and transmit a second PUSCHto the UE in a second mini-slot temporally adjacent to the firstmini-slot using a second frequency. Here, the same downlink data may beequally mapped to each PDSCH.

The present embodiment can be equally applied to a sidelink transmissionenvironment.

In this case, the transmitter may be a transmitting UE and the receivermay be a receiving UE. Data transmitted through sidelink may be PSSCH orPSSCH data, or data related to URLLC.

In addition, in the present embodiment, the range of frequencies usedfor frequency hopping may vary according to the size of a bandwidth part(BWP). For example, a transmitter may use frequency resourcescorresponding to both ends of a BWP for FH in order to maximize theeffect of frequency diversity. For example, as shown in FIG. 7 , when aBWP is composed of 10 PRBs (PRB #0 to PRB #9) and 4 times of repetitivetransmission are set, the transmitter may transmit the same data usingPRB #0, which is the lowest frequency resource in the BWP, in first andthird mini-slots and transmit the same data using PRB #9, which is thehighest frequency resource in the BWP, in second and fourth mini-slots.

Alternatively, the transmitter may transmit the same data using PRB #9in the first and third mini-slots and transmit the same data using PRB#0 in the second and fourth mini-slots, unlike FIG. 7 .

Meanwhile, when more frequency resources (resource Block (RB)) arenecessary for data transmission, the transmitter may use multiplefrequency resources while increasing the number of RBs from the end ofthe BWP. For example, in a situation where the BWP is composed of 10PRBs (PRB #0 to PRB #9) and 4 times of repetitive transmission are setas shown in FIG. 8 , the transmitter may transmit the same data usingPRB #0 and PRB #1 in the first and third mini-slots and transmit thesame data PRB #8 and PRB #9 in the second and fourth mini-slots.Alternatively, unlike FIG. 8 , the transmitter may transmit the samedata using PRB #8 and PRB #9 in the first and third mini-slots andtransmit the same data using PRB #0 and PRB #1 in the second and fourthmini-slots.

In addition, when there is a lot of URLLC traffic to which frequencyhopping is applied, it is necessary to prevent collision of frequencyresources. In particular, when resources to be used for frequencyhopping overlap between multiple UEs, it is necessary to adjust afrequency hopping range to prevent collision of frequency resources. Tothis end, when frequency hopping is applied, the frequency resource atthe end of a BWP may be basically used, but the frequency resource maybe changed if necessary. For example, if repetition number is set to 4for first and second UEs and frequency hopping resources of the first UEand frequency hopping resources of the second UE overlap, the first UEmay repetitively transmit the same data using frequency hopping in unitsof a mini-slot based on PRB #0 and PRB #9, which are frequency resourcesthat are basically set for frequency hopping, and the second UE mayrepetitively transmit the same data using frequency hopping in units ofa mini-slot based on PRB #1 and PRB #8, which are inner frequencyresources of basically set frequency resources, by adjusting thefrequency hopping range within the BWP, as shown in FIG. 9 .Alternatively, as shown in FIG. 10 , both the first UE and the second UEmay adjust the frequency hopping range, the first UE may repetitivelytransmit data using PRB #0 and PRB #8, and the second UE mayrepetitively transmits data using PRB #1 and PRB #9. Alternatively, asshown in FIG. 11 , the first UE and the second UE repetitively transmitthe same data using the same frequency resources while using differentfrequency hopping patterns.

Meanwhile, in case of repetitive transmission of the same data,frequency hopping may not be performed within one mini-slot in order toreduce complexity. When multiple mini-slots are used to repetitivelytransmit the same data, frequency hopping may be applied. When redundantor repetitive transmission occurs over several slots, a frequencydifferent from a frequency used in the previous slot may be used in thenext slot. That is, inter-slot FH may be applied. In this case, if abase station or a transmitting UE can trust channel information (achannel gain per each frequency, and the like), for example, frequencyhopping is not applied and a frequency resource with a satisfactorychannel condition may be allocated to repetitively transmit data.

Such frequency hopping-related information, for example, FH-relatedconfiguration information, may be semi-statically configured by a basestation using higher layer radio resource control (RRC) signaling andthe like and may be reported to a UE. In addition, control informationrelated to FH may be included in DCI and transmitted through a PDCCH. Inthe case of a sidelink transmission environment, the FH-relatedinformation may be transmitted by a base station to a UE through higherlayer signaling such as RRC or transmitted by a transmitting UE to areceiving UE. For example, the base station may inform a UE ofinformation on whether FH is applied, information on an FH pattern, andthe like through DCI. That is, the base station may include controlinformation for transmitting and receiving data in DCI and inform the UEof the control information through such a transmission method. In thiscase, a new field may be added to the DCI. When a transmitting UErepetitively or redundantly transmits data to a receiving UE, thetransmitting UE may inform the receiving UE of information on whether FHis applied, information on an FH pattern, and the like through sidelinkcontrol information (SCI).

In uplink transmission or downlink transmission, a base station mayinform a UE of the length of a mini-slot and the repetition number oftransmission through DCI. However, the repetition number of transmissionmay be set by being notifying through RRC in advance. As an example, thebase station may notify a default repetition number of transmissionthrough RRC, and when the default repetition number of transmissionneeds to be changed, may inform the UE of the actual repetition numberof transmission through DCI. In this case, information on a differencebetween the default repetition number of transmission and the actualrepetition number of transmission may be included in the DCI.

In sidelink transmission, a transmitting UE or a base station may informa receiving UE of the length of the mini-slot and the repetition numberof transmission through SCI or DCI.

Meanwhile, when frequency hopping is used, a separate demodulationreference signal (DMRS) may be applied to each repetitive transmission.However, when a transmitter repetitively transmits the same data to areceiver using the same frequency resource, the DMRS may not beseparately used. That is, repetition may be performed multiple timesusing one DMRS. However, in case of rapidly changing channels, the DMRSmay be separately used even if the same frequency resource is used. Thatis, a separate DMRS may be applied to each repetition.

Further, different numbers of DMRSs may be used according to services orQoS of the services during repetitions. For example, the DMRS may beseparately applied to each repetition in the case of high-speed movementand repetition may be performed multiple times using one DMRS in thecase of slow movement.

Meanwhile, in the case of very important information, the sameinformation may be repetitively transmitted in the frequency domain andthe time domain. For example, a transmitter may allocate multiplefrequency resources and transmit the same information multiple timesthrough the frequency resources. For example, as shown in FIG. 12 , thetransmitter may map the same data to PRB #0 and PRB #9 and transmit thesame data through the first to fourth mini-slots. This method may bemore suitable in an mm-Wave environment with many frequency resourcesand small time resources.

As another example, the transmitter may transmit the same informationmultiple times using both different frequency and time resources. Forexample, as shown in FIG. 13 , the transmitter may perform frequencyhopping using PRB #0 and PRB #9 when repetitively transmitting firstdata and repetitively transmit second data identical to the first datausing an optimal frequency resource (RPB #5 in FIG. 13 ) based on CQI.

In the above-described embodiment, a frequency hopping resource may bederived based on Table 1 below.

TABLE 1 Numbers of PRBs in Value of NUL_hop Frequency offset initialactive UL BPW Hopping Bits for 2^(nd) hop N_(BWP) ^(size) < 50 0|N_(BWP) ^(size)| 1 −|N_(BWP) ^(size)| N_(BWP) ^(size) ≥ 50 00 |N_(BWP)^(size)/2| 01 |N_(BWP) ^(size)/4| 10 −|N_(BWP) ^(size)/4| 11 Reserved

Referring to Table 1, a frequency hopping offset during repetition maybe determined based on the number of RPBs in an active uplink BWP. Inaddition, a frequency hopping pattern may be determined according to thevalue of a hopping bit. This frequency hopping resource determinationmethod may be equally applied to downlink.

FIG. 14 is a flowchart showing a data transmission method according toan embodiment of the present disclosure.

According to the present embodiment, a transmitter may repetitivelytransmit the same data to a receiver through various methods accordingto channel states. Here, the transmitter may be a base station or atransmitting UE and the receiver may be a base station or a receivingUE.

Hereinafter, as an example, a case in which a UE repetitively transmitsuplink data to a base station will be described with reference to FIG.14 .

The base station may determine whether to apply frequency hopping touplink data to be transmitted by the corresponding UE based on a CQIreport received from the UE. To this end, the UE may check a channelstate and transmit the CQI report to the base station (S1410). The basestation may check the channel state based on a CQI value included in theCQI report received from the UE, determine that repetition of the datais performed without applying frequency hopping if the channel state isgood, and determine that frequency hopping is applied during repetitionif the channel state is not good or channel information is unknown orunreliable. In addition, the base station may transmit DCI includinginformation on the repetition number of transmission of uplink data andinformation on frequency hopping to the corresponding UE. Here, the DCImay further include information on the length of a mini-slot used forrepetition in addition to the information on the repetition number oftransmission and the information on frequency hopping. In addition, theinformation on frequency hopping may include information on whetherfrequency hopping is applied and/or information on a frequency hoppingpattern.

Upon reception of the DCI from the base station, the UE may determinewhether to perform frequency hopping based on the DCI (S1420). If it isdetermined that repetition is performed without applying frequencyhopping, the UE may repetitively transmit the same data using an optimalfrequency resource (S1430). In this case, the UE may repetitivelytransmit the same data using a plurality of frequency and/or timeresources according to the importance of the data.

However, if it is determined that frequency hopping is applied duringrepetitive transmission, the UE may transmit first data in a firstmini-slot using a first frequency (S1440) and transmit the same data asthe first data in a second mini-slot temporally adjacent to the firstmini-slot using a second frequency according to frequency hopping(S1450). In this case, the UE may repetitively transmit the same datausing at least one of the frequency hopping methods of FIGS. 7 to 13 .

For example, when the DCI is received from the base station, the UE mayconfigure a plurality of PUSCHs corresponding to the repetition numberof transmission based on the information on the repetition number oftransmission included in the DCI and determine frequency resources fortransmission of the plurality of PUSCHs based on the information onfrequency hopping included in the DCI. In this case, the uplink data maybe equally mapped to the plurality of PUSCHs. In addition, the range offrequency hopping during repetition may be changed depending on the sizeof an active BWP for transmission of the corresponding uplink data.

<Communication Method Based on Adaptively Controlled Number ofTransmissions>

FIG. 15 is a flowchart showing a data transmission method according toan embodiment of the present disclosure.

In the present embodiment, a transmitter may transmit the sameinformation (same data) to a receiver redundantly or repetitively. Whena UE transmits the same data to a base station repetitively orredundantly, the data may be PUSCH or PUSCH data. Alternatively, thedata may be URLLC-related data. When the base station repetitively orredundantly transmits the same data to the UE, the data may be PDSCH orPDSCH data. Alternatively, the data may be URLLC-related data. When atransmitting UE repetitively or redundantly transmits the same data to areceiving UE, the data may be PSSCH or PSSCH data or may be data relatedto URLLC.

FIG. 15 illustrates an example of a case where the transmitter is a basestation and the receiver is a UE.

Referring to FIG. 15 , the repetition number of transmission and amaximum repetition number of transmission may be semi-statically orstatically set by the base station through radio resource control (RRC)by default. For example, the base station may inform the UE ofinformation on a default repetition number of transmission and/or themaximum repetition number of transmission through higher layer signalingsuch as an RRC message (S1510). That is, the maximum repetition numberof transmission or the default repetition number of transmission may beset through RRC, or both may be set if necessary.

For example, the base station may configure a plurality of PDSCHs forfirst data based on information on the default repetition number oftransmission or the maximum number of times of repetitive transmission.That is, the first data may be equally mapped to the plurality ofPDSCHs. The base station may repetitively transmit the first data bytransmitting the plurality of PDSCHs to which the first data is equallymapped to the UE using different time and/or frequency resources(S1520). Here, the maximum repetition number of transmission may be setas the default number of times of repetitive transmission. In this case,the base station may transmit only information on the maximum repetitionnumber of transmission through an RRC message, and the UE may recognizethat the maximum repetition number of transmission is used as thedefault number of times of repetitive transmission.

A receiver may transmit ACK/NACK in each repetition and a transmittermay determine an optimal repetition number of transmission inconsideration of this. As an example, referring to FIG. 5 , when theplurality of PDSCHs is received from the base station, the UE may decodethe PDSCHs (S1530), transmit HARQ ACK for a successfully received PDSCH,and transmit HARQ NACK for a PDSCH having an error (S1540). The basestation may determine the repetition number of transmission for seconddata (data repetitively transmitted after the first data) based on thenumber of HARQ ACKs and/or the number of HARQ NACKs received from the UE(S1550). In this case, the UE may use a chase combining (CC) methodand/or an incremental redundancy (IR) method in determining the need forretransmission of corresponding data. The CC method may be used when thesame redundancy version is applied to all of the plurality of PDSCHs,and the IR method may be used when different redundancy versions areapplied to the plurality of PDSCHs. For example, if an error isgenerated in the first PDSCH when the UE decodes the plurality ofPDSCHs, the UE may combine the first PDSCH with the second PDSCH tocorrect the error generated in the first PDSCH and/or the second PDSCH.When errors are generated in all of the plurality of PDSCHs, but thecorresponding data has been successfully decoded as a result ofcombining the PDSCHs, the UE may transmit HARQ ACK instead of HARQ NACKfor the last received PDSCH. In this case, the base station can beprevented from unnecessarily retransmitting the corresponding data whilerecognizing that the channel state is not good through HARQ feedbackbecause the UE has successfully received the data.

After performing repetitive transmission, the transmitter determinesthat the channel state is very good if the number of ACKs for therepetitive transmission is equal to or greater than a reference value orif a ratio between the number of ACKs and the number of NACKs includedin the corresponding feedback is equal to or greater than a referenceratio, and when transmitting the next data in a similar channelenvironment, reduce the number of repetitions and perform repetitivetransmission. However, if the number of ACKs is less than the referencevalue or reference ratio, the transmitter may determine that the channelcondition is not good, and when transmitting the next data (second data)in a similar channel environment (an environment corresponding to thechannel environment when the first data is transmitted), increase thenumber of repetitions and perform repetitive transmission. That is, therepetition number of transmission for the second data may be changedwhen a channel environment when the second data is transmittedcorresponds to a channel environment when the first data transmitted.

For example, when the base station receives a number of HARQ ACKs equalto or greater than the reference value for the plurality of PDSCHs fromthe UE, the base station may reduce the repetition number oftransmission for the second data to be lower than the repetition numberof transmission for the first data if the second data needs to berepetitively transmitted in a channel environment similar to that whenthe first data is repetitively transmitted. As another example, when thebase station receives a number of HARQ ACKs less than the referencevalue for the plurality of PDSCHs from the UE, the base station mayincrease the repetition number of transmission for the second data to begreater than the repetition number of transmission for the first data ifthe second data needs to be repetitively transmitted in a channelenvironment similar to that when the first data is repetitivelytransmitted. Thereafter, the base station may inform the UE ofinformation on the repetition number of transmission for the second datathrough DCI, configure a number of PDSCHs corresponding to therepetition number of transmission using the second data, and transmitthe PDSCHs to the UE (S1560).

In this case, the base station may change the repetition number oftransmission after performing repetition by the default number of timesof repetitive transmission. The number of initial transmissions followedby update of the repetition number of transmission may be set as anotherparameter. (e.g., 1, 2, 4, 6, . . . )

For example, if a parameter for update of the repetition number oftransmission is set to “2”, the base station may repetitively transmitthe first data and the second data by the default number of times ofrepetitive transmission, respectively, and then determine the number ofrepetitions for third data based on the number of HARQ ACKs and/or NACKsfor the first data and/or the second data.

For repetition thereafter, the base station may change the same in realtime within a range set through RRC, and the corresponding informationmay be included in DCI and signaled to the UE. For example, the basestation may initially set the repetition number to a certain numberthrough RRC and then signal only a difference between the repetitionnumber of current repetitive transmission and the repetition number ofprevious transmission through DCI. Alternatively, only up or down forthe repetition number of transmission may be signaled. For example, thebase station may set the repetition number of transmission to (2, 4, 6,8) through RRC and set the default repetition number of transmission to“2”. In this case, when the base station indicates “up” for therepetition number of transmission through DCI, the UE may change thedefault repetition number of transmission from “2” to “4”.

In addition, the base station may signal whether repetitive transmissionis activated/deactivated through DCI. Therefore, according to thepresent embodiment, the repetition number of transmission can beoptimized and thus the number of ACKs/NACKs can be reduced.

Meanwhile, in the present embodiment, repetitive transmission isapplicable to both the time axis and the frequency axis. That is, thetransmitter may dynamically set the repetition number of transmission ofthe same information using different time and/or frequency resources.

The more a high-frequency band is used during repetitive transmission,the more repetition may occur on the frequency axis. It may beadvantageous to perform repetitive transmission on the frequency axis toachieve ultra-low latency. However, in some cases, a time resource maybe repetitively used. For example, the transmitter may transmit firstdata using a first frequency source on a first slot or a first mini-slotand transmit the same data as the first data using a second frequencyresource. As another example, the transmitter may transmit the firstdata using the first frequency resource in the first slot or the firstmini-slot and transmit the same data as the first data using the firstfrequency resource or the second frequency resource in a second slot ora second mini-slot temporally adjacent to the first slot or the firstmini-slot.

Meanwhile, as another embodiment, the repetition number of transmissionmay be changed according to channel state such as CQI. For example, thetransmitter may decrease the repetition number of transmission when thechannel state is good and increase the repetition number of transmissionwhen the channel state is not good. Information on increase and/ordecrease in the repetition number of transmission may be transmitted tothe receiver through DCI, SCI, UCI, or the like. In this case, it may bemore suitable for the number of repetitions to be set semi-staticallyrather than dynamically.

FIG. 16 is a flowchart showing a data transmission method according toanother embodiment of the present disclosure.

FIG. 16 shows a case where a transmitter is a UE and a receiver is abase station. However, repetitive transmission may be performed in asimilar manner even when both the transmitter and the receiver are UEs.

Referring to FIG. 16 , the repetition number of transmission and amaximum repetition number of transmission may be semi-statically orstatically set by the base station through RRC by default. For example,the base station may inform the UE of a default repetition number oftransmission and/or the maximum repetition number of transmissionthrough higher layer signaling such as RRC (S1610). That is, a value setthrough RRC may be the maximum repetition number of transmission and/orthe default number of times of repetitive transmission.

The UE may configure a plurality of PUSCHs for first data based oninformation on the maximum repetition number of transmission or thedefault repetition number of transmission (S1620). Here, the first datamay be equally mapped to the plurality of PUSCHs. The UE mayrepetitively transmit the plurality of PUSCHs to the base station usingdifferent time and/or frequency resources (S1630).

Upon reception of the plurality of PUSCHs from the UE, the base stationmay decode them (S1640) and may transmit feedback (a plurality ofACKs/NACKs) for repetitive transmissions (the plurality of PUSCHs) tothe UE (S1650). In this case, the base station may determine an optimalnumber of times of repetitive transmission based on the number of ACKsand/or the number of NACKs included in the feedback (S1660).

For example, when the plurality of PUSCHs is received from the UE, thebase station may decode them, transmit a HARQ ACK for a successfullyreceived PUSCH, and transmit a HARQ NACK for a PUSCH having an error.The base station may determine the repetition number of transmission forsecond data based on a channel state determined based on the PUSCHsreceived from the UE, the number of transmitted HARQ ACKs, and/or thenumber of transmitted HARQ NACKs.

In addition, the base station may use the CC method and/or the IR methodin determining the necessity of retransmission of the correspondingdata. For example, when an error is generated in the first PUSCH duringdecoding of the plurality of PUSCHs, the base station may combine thefirst PUSCH with the second PUSCH to correct the error generated in thefirst PUSCH and/or the second PUSCH. If errors are generated in all ofthe plurality of PUSCHs, but the data has been successfully decoded as aresult of combining the PUSCHs, the base station may transmit a HARQ ACKinstead of a HARQ NACK for the last received PUSCH such that the UE doesnot unnecessarily retransmit the data.

The transmitter may inform the receiver of information on the repetitionnumber of transmission for the second data through control informationsuch as DCI.

Although FIG. 16 illustrates that the repetition number of transmissionis determined by the base station, for example, if the transmitter is atransmitting UE and the receiver is a receiving UE, the repetitionnumber of transmission may be determined by the transmitting UE or thereceiving UE.

<CBG-Based Transmission Method and Apparatus Therefor>

FIG. 17 is a diagram for describing the concept of a code block groupapplied to the present disclosure.

In the NR system, retransmission due to HARQ is performed in units of acode block group (CBG) which is smaller than the unit of a transportblock (TB). As an example, referring to FIG. 17 , one TB may besegmented into eight code blocks (CBs), and three code blocks may begrouped into one CBG. However, this is merely an example, and one CBGmay be composed of one code block and one TB may be composed of one CBG.

FIG. 18 is a diagram illustrating a configuration of a PDSCH servingcell applied to an embodiment of the present disclosure and FIG. 19 is adiagram illustrating a configuration of a PUSCH serving cell applied toan embodiment of the present disclosure.

Referring to FIG. 18 and FIG. 19 , in both uplink transmission anddownlink transmission, a maximum of 2, 4, 6, or 8 CBGs per one TB may beconfigured by higher layer signaling. A CBG is a group of 2, 4, 6, or 8code blocks, used as a unit of HARQ retransmission, and reflected inDCI.

DCI format 0_1 used for PUSCH scheduling is shown in Table 2 below, andDCI format 1_1 used for PDSCH scheduling is shown in Table 3 below.

TABLE 2 Field Bits Usage Identifier for DCI 1 0 is set for UL DCIformats Carrier indicator 0 or 3 UL/SUL indicator 0 or 1 1 bit if UE isconfigured with SUL, 0 otherwise Bandwidth part 0, 1, or indicator 2Frequency domain Variable resource assignment Time domain resource 0, 1,2, assignment 3, or 4 Frequency hopping 0 or 1 0 when frequency hoppingnot flag enabled, else 1 Modulation and coding 5 scheme New dataindicator 1 Redundancy version 2 HARQ process number 4 1^(st) downlink 1or 2 assignment index 2^(nd) downlink 0 or 2 assignment index TPCcommand for 2 scheduled PUSCH SRS resource indicator Variable Precodinginformation Variable and number of layers Antenna ports Variable CSIrequest 0, 1, 2, 3, 4, 5, or 6 CBG transmission 0, 2, 4, Determined byhigher layer parameter information 6, or 8maxCodeBlockGroupsPerTransportBlock PTRS-IMRS Variable associationBeta_offset indicator 0 or 2 0 if betaOffset = semestatic, 2 otherwiseIMRS sequence 0 or 1 0 bit if the higher layer parameter initializationtransform precoder is enabled1 bit if he higher layer parametertransform precoder is disenabled UL-SUH indicator 1

TABLE 3 Field Bits Usage Identifier for DCI formats 1 value as 1,indication of DL DCI Carrier Indicator 0 or 0 Bandwidth part indicator0, 1, or 3 Frequency domain resource Variable Similar to DCI 1_0 fieldassignment Time domain resource 0, 1, 2, 3, assignment or 4 VRB-to-PRBmapping 0 or 1 0 if prb-BundingType is not configured or is set tostatic, 1 otherwise PRB bundling size indicator 0 or 1 Rate matchingindicator 0, 1, or 2 ZP CSI-RS trigger 0, 1, or 2 Modulation and codingscheme 5 [TB1] New data indicator [TB1] 1 Redundancy version [TB1] 2Modulation and coding scheme 5 [TB2] New data indicator [TB2] 1Redundancy version [TB2] 2 HARQ process number 4 Downlink assignmentindex 0, 2, or 4 TPC command for scheduled 2 PUSCH PUCCH resourceindicator 3 PDSCH-to-HARQ_feedback 0, 1, 2, or timing indicator 3Antenna ports 4, 5, or 6 SRS request 2 CBG transmission information 0,2, 4, 6, or 8 CBG flushing out information 0 or 1 IMRS sequenceinitialization 0 or 1

However, since URLLC data generally has a smaller data size than eMBBdata and requires a low latency, the unit (or size) of the CBG needs tobe set to a unit smaller than that of eMBB. Therefore, according to thepresent embodiment, a CBG for URLLC use may be set differently from aCBG for eMBB. As an example, the CBG for URLLC may be composed of 1, 2,3 or 4 code blocks. Alternatively, in the case of URLLC, a maximumnumber of CBGs included in one TB may be set to 4, 8, 12, or 16. Thatis, when URLLC data is retransmitted, a maximum number of CBGs includedin the TB is determined according to the TB size, and as a result, thesize unit of retransmitted data may be set to be smaller than that ofeMBB.

For example, in the case of URLLC, if the TB size is the same as that ofeMBB, a maximum number of CBGs per TB for URLLC may be set to be largerthan that of eMBB. If the TB size is smaller than that of eMBB, themaximum number of CBGs per TB for URLLC may be set to be similar to thatof eMBB. That is, according to an embodiment, the maximum number of CBGsper TB for URLLC may be set by RRC separately from the maximum number ofCBGs per TB for eMBB.

Information on CBGs for URLLC may be indicated by RRC, and if necessary,DCI settings may be changed or added to reflect this. As an example, afield with respect to CBG transmission information for URLLC may beadded to DCI format 0_1 of Table 1 and/or DCI format 1_1 of Table 2. Forexample, the CBG transmission information for URLLC may be set to anyone of 0, 2, 4, 6, 8, 10, 12, 14 and 16 bits and indicate that thecorresponding CBG is to be retransmitted when URLLC data isretransmitted in the form of a bitmap.

Meanwhile, the maximum number of CBGs per TB for URLLC may be setthrough RRC separately from the maximum number (2, 4, 6, 8) of CBGs perTB currently set for eMBB. As an example, the maximum number of CBGs perTB for URLLC may be configured in the RRC message of FIG. 6 and/or FIG.7 .

In addition, {n1, n2, n4, n8} may be added as information on the numberof CB s (CodeBlocksPerCodeBlockGroup for URLLC) per CBG. As anotherexample, {n4, n8, n12, n16} may be added to the RRC message of FIG. 6and/or FIG. 7 as information on the maximum number of CBGs(maxCodeBlockGroupsPerTransportBlock for URLLC) per TB for URLLC.

As another example, instead of separately setting CBGs for URLLC throughRRC, data may be mapped to a separate table for URLLC such that themaximum number (2, 4, 6, 8) of CBGs per TB is recognized as (4, 8, 12,16) if the data corresponds to URLLC. For example, if the number of CBGsper TB for eMBB data is set to “2” by a base station, a UE may set thenumber of CBGs per TB to “4” for URLLC data based on information set inthe table for URLLC and retransmit only a CBG including data having anerror among four CBGs.

When this method is applied, retransmission time of URLLC data due toHARQ can be reduced and retransmission of URLLC data having a relativelysmall data size can be performed more efficiently.

FIG. 20 is a diagram for describing a case of retransmitting eMBB dataaccording to an embodiment and FIG. 21 is a diagram illustrating a caseof retransmitting URLLC data according to an embodiment.

Referring to FIG. 20 , a case in which one TB is configured by 2 CBGsand one CBG is composed of 4 CBs is illustrated. When a transmitterinitially transmits eMBB data, CBs #0 to CB #7 are transmitted to areceiver because the transmitter performs transmission in units of a TB.

In this case, if an error is generated in at least one of CB #0 to CB#3, that is, if the transmitter receives a HARQ NACK for at least one ofCB #0 to CB #3 from the receiver, the transmitter retransmits only CGB#1 including the corresponding CB. On the other hand, as shown in FIG.21 , if the CB (CB #1) having an error corresponds to URLLC data in thesame situation as in FIG. 20 , the transmitter may configure a CGBhaving a size smaller than the size of the CBG for eMBB data andretransmit the corresponding data. To this end, the transmitter mayincrease the number of CBGs of the initially transmitted TB byincreasing a maximum number of CGBs per TB when retransmitting the URLLCdata or may decrease the number of CB s per CGB. Therefore, according tothe present embodiment, since the URLLC data can be retransmitted in asmaller unit as compared to a case in which eMBB data is retransmitted,retransmission with lower latency and higher efficiency can beperformed.

FIG. 22 is a flowchart showing a data transmission method according toan embodiment of the present disclosure.

Hereinafter, a method in which a transmitter transmits data to areceiver according to the present embodiment will be described withreference to FIG. 22 . In the present embodiment, when the transmitteris a base station, the receiver may be a UE. When the transmitter is aUE, the receiver may be a base station or another UE. When the receiveris a base station, the data may be URLLC data, uplink data, a PUSCH orPUSCH data. When the receiver is another UE, the data may be URLLC data,sidelink data, a PSSCH or PSSCH data. When the transmitter is a basestation, the data may be URLLC data, downlink data, a PDSCH or PDSCHdata.

For example, when the transmitter is a UE and the receiver is a basestation, the UE transmits uplink data to the base station (S2210) andreceives a feedback for the uplink data from the base station (S2220).Here, the feedback may be HARQ ACK or HARQ NACK for the uplink data.

The UE may determine whether to retransmit the uplink data based on thefeedback (S2230). If the feedback for the uplink data transmitted to thebase station is ACK, the UE determines that the corresponding data hasbeen successfully transmitted and omits retransmission of thecorresponding data. That is, the data is not retransmitted. However, ifNACK is included in the feedback, the UE may retransmit thecorresponding data. In this case, the UE may adjust the size of the CBGof the uplink data based on the type of the uplink data that needs to beretransmitted and perform retransmission in units of the adjusted CBG.For example, when the data corresponding to the NACK is eMBB data, theUE may retransmit a CGB including a code block having an error to thebase station, as shown in FIG. 20 . However, when the data correspondingto the NACK is URLLC data, the UE may adjust the size of the CBG asshown in FIG. 21 (S2240) and perform retransmission based on theadjusted CGB (S2250). In this case, the size of the CBG forretransmission of the URLLC data may be set to be smaller than the sizeof the CBG for retransmission of eMBB data such that the URLLC data canbe transmitted more rapidly with fewer resources. Information on this(information on the size of the CBG for retransmission of the URLLCdata) may be received from the base station through at least one of anRRC message and DCI. In this case, the code block group forretransmission of eMBB data may include 2, 4, 6, or 8 code blocks, andthe code block group for retransmission of the URLLC data may include 1,2, 3 or 4 code blocks.

As another example, when the transmitter is a base station and thereceiver is a UE, when a feedback for downlink data transmitted to theUE is received from the UE, the base station determines whether toretransmit the data based on the feedback. If the feedback is ACK, thebase station determines that the corresponding data has beensuccessfully transmitted and transmits the next data. However, if NACKis included in the feedback, the base station may adjust the size of theCBG based on the type of the corresponding data and performretransmission in units of the adjusted CBG. For example, when the datacorresponding to NACK is eMBB data, the base station may retransmit aCGB including a code block having an error to the UE as shown in FIG. 20. However, when the data corresponding to NACK is URLLC data, the basestation may adjust the size of the CBG as shown in FIG. 21 (S2240) andperform retransmission based on the adjusted CGB (S2250). In this case,the base station may transmit information on the size of the CBG forretransmission of URLLC data to the UE through DCI. Alternatively, theinformation on the size of the CBG for retransmission of the URLLC datamay be transmitted to the UE in advance through an RRC message. Here,the information on the size of the CBG for retransmission of the URLLCdata may be information on a maximum number of code block groups per TBfor the URLLC data and may be set separately from information on amaximum number of code block groups per TB for eMBB data.

FIG. 23 is a block diagram showing a wireless communication system inwhich an embodiment of the present disclosure is implemented.

Referring to FIG. 23 , a UE 2300 includes a memory 2305, a processor2310, and a radio frequency (RF) unit 2315. The memory 2305 is connectedto the processor 2310 and stores various types of information fordriving the processor 2310. The RF unit 2315 is connected to theprocessor 2310 to transmit and/or receive radio signals. For example,the RF unit 2315 may receive configuration and/or control informationsuch as an RRC message and DCI, and a downlink signal such as a PDSCHdescribed in the present description from a base station 2350.

In addition, the RF unit 2315 may transmit an uplink signal such as aCQI report and a PUSCH described in the present description the basestation 2350 or may transmit/receive a PSSCH to/from another UE (notshown).

The processor 2310 implements functions, processes and/or methods of theUE proposed in the present description. Specifically, the processor 2310performs the operation of the UE according to FIGS. 7 to 22 . Forexample, the processor 2310 may configure a plurality of PUSCHs or aplurality of PSSCHs according to an embodiment of the present disclosureand transmit the same using the data transmission method according toany one of FIGS. 7 to 23 . In all embodiments of the presentdescription, the operation of the UE 2300 may be implemented by theprocessor 2310.

The memory 2305 may store control information and configurationinformation according to the present description and may provide thecontrol information and the configuration information to the processor2310 at the request of the processor 2310.

The base station 2350 includes a processor 2355, a memory 2360, and aradio frequency (RF) unit 2365. The memory 2360 is connected to theprocessor 2355 and stores various types of information for driving theprocessor 2355. The RF unit 2365 is connected to the processor 2355 totransmit and/or receive radio signals. The processor 2355 implements thefunctions, processes and/or methods of the base station proposed in thepresent description. In the above-described embodiments, the operationof the base station may be implemented by the processor 2355. Theprocessor 2355 may generate an RRC message, downlink controlinformation, and the like described in the present description orconfigure a plurality of PDSCHs.

The processor may include an application-specific integrated circuit(ASIC), other chipsets, logic circuits, and/or data processing devices.The memory may include a read-only memory (ROM), a random access memory(RAM), a flash memory, a memory card, a storage medium, and/or otherstorage devices. The RF unit may include a baseband circuit forprocessing a radio signal. When an embodiment of the present disclosureis implemented as software, the above-described technique may beimplemented as a module (a process, a function, etc.) that performs theabove-described functions. The module may be stored in a memory andexecuted by a processor. The memory may be provided inside or outsidethe processor and may be connected to the processor by variouswell-known means.

In the exemplary system described above, the methods are described as aseries of steps or blocks on the basis of flowcharts, but the presentdisclosure is not limited to the order of steps, and some steps mayoccur in a different order or concurrently with other steps as describedabove. In addition, those skilled in the art will understand that thesteps shown in the flowcharts are not exclusive and that other steps maybe included or one or more steps in the flowcharts may be deletedwithout affecting the scope of the present disclosure.

What is claimed is:
 1. A method of transmitting data by a user equipmentin a wireless communication system comprising: receiving, from a basestation, configuration information adjusting a range of frequencyhopping; receiving, from the base station, information for number ofrepetitions of uplink data on the frequency hopping; receiving, from thebase station, downlink control information for the frequency hopping;configuring physical uplink shared channel (PUSCH) repetitions totransmit the uplink data correspond to the number of repetitions; andperforming the frequency hopping for the PUSCH repetitions, wherein theperforming frequency hopping includes: a first PUSCH repetition, using aplurality of resource blocks (RBs) including a first basic resourceblock (RB), and a second PUSCH repetition, using a plurality of RBsincluding a second basic RB which is apart from the first basic RB withan offset, and wherein the offset between the first basic RB and thesecond basic RB is determined based on a size of bandwidth part (BWP)which is activated for transmitting the uplink data.
 2. The method ofclaim 1, wherein the downlink control information includes informationon length of mini-slot used for repetition transmissions of the uplinkdata, and the PUSCH repetitions are performed in unit of the mini-slot.3. The method of claim 1, wherein the plurality of RBs including thefirst basic RB and the plurality of RBs including the second basic RBare frequency resources corresponding to both ends of the activated BWPrespectively.
 4. The method of claim 1 further comprises: transmittingchannel quality information to the base station, wherein the downlinkcontrol information for the frequency hopping is determined based on thechannel quality information.
 5. The method of claim 1, wherein differentdemodulation reference signal (DM-RS) is applied to each PUSCHrepetition.
 6. The method of claim 1 further comprises: receiving fromthe base station information on default number of repetitions of theuplink data, wherein the downlink control information includesinformation on a difference value between the default number ofrepetitions and actual number of repetitions of the uplink data.
 7. Auser equipment transmitting data in a wireless communication system, theuser equipment comprising: a Radio Frequency (RF) unit configured toreceive from a base station configuration information adjusting a rangeof frequency hopping, to receive from the base station information fornumber of repetitions of uplink data on the frequency hopping, and toreceive from the base station downlink control information for thefrequency hopping; and a processor configured to configure physicaluplink shared channel (PUSCH) repetitions to transmit the uplink datacorrespond to the number of repetitions, and to perform the frequencyhopping for the PUSCH repetitions, wherein for a first PUSCHrepetition,. the processor uses a plurality of resource blocks (RBs)including a first basic RB, and for a second PUSCH repetition, theprocessor uses a plurality of RBs including a second basic RB which is aapart from the first basic RB with an offset, and wherein the offsetbetween the first basic RB and the second basic RB is determined basedon a size of bandwidth part (BWP) which is activated for transmittingthe uplink data.
 8. The user equipment of claim 7, wherein the downlinkcontrol information includes information on length of mini-slot used forrepetition transmission of the uplink data, and the PUSCH repetitionsare performed in unit of the mini-slot.
 9. The user equipment of claim7, wherein the plurality of RBs including the first basic RB and theplurality of RBs including the second basic RB are frequency resourcescorresponding to both ends of the activated BWP respectively.
 10. Theuser equipment of claim 7, wherein the RF unit transmits channel qualityinformation to the base station, and wherein the downlink controlinformation for the frequency hopping is determined based on the channelquality information.
 11. The user equipment of claim 7, whereindifferent demodulation reference signal (DM-RS) is applied to each PUSCHrepetition.
 12. The user equipment of claim 7, wherein the RF unitreceives from the base station information on default number ofrepetitions of the uplink data, and wherein the downlink controlinformation includes information on a difference value between thedefault number of repetitions and actual number of repetitions of theuplink data.
 13. A method of receiving data by a base station in awireless communication system comprising: transmitting, to a userequipment, configuration information adjusting a range of frequencyhopping transmitting to the user equipment, information number ofrepetitions of uplink data on the frequency hopping; transmitting, tothe user equipment, downlink control information for the frequencyhopping; and configuring physical uplink shared channel (PUSCH)repetitions for the uplink data correspond to the number of repetitions,wherein a first PUSCH repetition of the frequency hopping uses aplurality of resource blocks (RBs) including a first basic RB, and for asecond PUSCH repetition of the frequency hopping uses a plurality of RBsincluding a second basic RB which is a apart from the first basic RBwith an offset, and wherein the offset between the first basic RB andthe second basic RB is determined based on a size of bandwidth part(BWP) which is activated for transmitting the uplink data.
 14. Themethod of claim 13, wherein the downlink control information includesinformation on length of mini-slot used for repetition transmission ofthe uplink data, and the PUSCH repetitions are performed in unit of themini-slot.
 15. The method of claim 13, wherein the plurality of RBsincluding the first basic RB and the plurality of RBs including thesecond basic RB are frequency resources corresponding to both ends ofthe activated BWP respectively.
 16. The method of claim 13, furthercomprises: receiving channel quality information from the userequipment, wherein the downlink control information on the frequencyhopping is determined based on the channel quality information.
 17. Themethod of claim 13, wherein different demodulation reference signal(DM-RS) is applied to each PUSCH repetition.
 18. The method of claim 13,further comprises: transmitting to the user equipment information ondefault number of repetitions of the uplink data, wherein the downlinkcontrol information includes information on a difference value betweenthe default number of repetitions and actual number of repetitions ofthe uplink data.
 19. A base station receiving data in a wirelesscommunication system, the base station comprising: a Radio Frequency(RF) unit configured to transmit to a user equipment configurationinformation adjusting a range of frequency hopping, to transmit to theuser equipment information number of repetitions of uplink data on afrequency hopping, and to transmit to the user equipment downlinkcontrol information for the frequency hopping; and a processorconfigured to configure physical uplink shared channel (PUSCH)repetitions for the uplink data correspond to the number of repetitions,wherein for a first PUSCH repetition of the frequency hopping, theprocesser uses a plurality of resource blocks (RBs) including a firstbasic RB, and for a the second PUSCH repetition of the frequencyhopping, the processor uses a plurality of RBs including a second basicRB which is apart from the first basic RB with an offset, and whereinthe offset between the first basic RB and the second basic RB isdetermined based on a size of bandwidth part (BWP) which is activatedfor transmitting the uplink data.
 20. The base station of claim 19,wherein the downlink control information includes information on lengthof mini-slot used for repetition transmission of the uplink data, andthe PUSCH repetitions are performed in unit of the mini-slot.
 21. Thebase station of claim 19, wherein the plurality of RBs including thefirst basic RB and the plurality of RBs including the second basic RBare frequency resources corresponding to both ends of the activated BWPrespectively.
 22. The base station of claim 19, wherein the RF unitreceives channel quality information from the user equipment, whereinthe downlink control information on the frequency hopping is determinedbased on the channel quality information.
 23. The base station of claim19, wherein different demodulation reference signal (DM-RS) is appliedto each PUSCH repetition.
 24. The base station of claim 19, wherein theRF unit transmits to the user equipment information on default number ofrepetition of the uplink data, and wherein the downlink controlinformation includes information on a difference value between thedefault number of repetitions and actual number of repetitions of theuplink data.